1. Technical Field
The disclosure relates to light emitting diodes, and particularly to a light emitting diode with a transparent protecting layer and a transparent conductive layer whose structures are modified to thereby increase light extraction efficiency of the light emitting diode, and a method for manufacturing the light emitting diode.
2. Description of the Related Art
A conventional light emitting diode (LED) includes a substrate, a light emitting structure having an N-type semiconductor layer, an active layer and a P-type semiconductor layer formed on the substrate in sequence, and two electrodes (i.e., N-type and P-type electrodes) respectively connected to the N-type and P-type semiconductor layers. There are several factors affecting the light extraction efficiency of the light emitting diode, such as material of the semiconductor layer, construction of the light emitting structure, transparency of the light emitting diode, or total reflection of the light radiated from the light emitting structure.
Generally, to achieve a homogenous current distribution in the semiconductor layers without decreasing light extraction efficiency thereof, a transparent indium tin oxide (ITO) layer is formed between the P-type electrode and the P-type semiconductor layer. A transparent protecting layer is further formed on the transparent conductive layer to protect the light emitting diode. However, in fact, both the transparent conductive layer and the transparent protecting layer will result in total reflection when the light exits therefrom, thereby decreasing light extraction efficiency of the light emitting diode.
Therefore, it is desirable to provide a light emitting diode and a method for manufacturing a light emitting diode with high light extraction efficiency.